In recent years, fine suspended particulate matter (PM2.5) becomes an important environmental air pollution problem in the world. If people exposed themselves to the polluted environment for a long time, the people will be under the risk of lung cancer, stroke, heart disease, chronic respiratory disease, respiratory infections and asthma and other diseases. PM2.5 pollution is a significant impact on human health. Therefore, the detectable PM 2.5 machine becomes more important. The existing PM2.5 detectors are, for example, weighted type detectors or optical type detectors.
However, the weighted type detector is heavy and expensive. The accuracy of optical type detector is not good enough. Also, the optical type detector fails to be integrated with the chip directly, and needs a fan to provide air flow.